The use of a medical balloon for delivery of an expandable, implantable medical device such as a stent, stent-graft, graft or vena cava filter to a desired bodily location is well known in the art. Typically, an expandable, implantable medical device such as a stent is disposed about a balloon which in turn is mounted on a catheter tube. The catheter is inserted into a bodily vessel and advanced to a desired location. The balloon is then inflated so as to expand or assist in expanding the medical device.
In balloon expansion of an expandable, implantable medical device, it is important that the medical device be accurately positioned on the body portion of a balloon. Failure to properly position the medical device on the balloon may result in a non-uniform expansion of the medical device. If a portion of the medical device extends over the cone or waist portions of the balloon, for example, that portion of the medical device may not be fully expanded by the balloon.
Unfortunately, the proper positioning of such a medical device on a balloon can be a challenging task because the medical device is typically mounted on an uninflated balloon. In the uninflated state of the balloon, it is difficult to discern where the proximal and distal cones end and where the body portion of the balloon begins
It is also important to properly position the balloon itself on the catheter so that the various portions of the balloon are disposed in desired locations along the catheter and are properly aligned. Again, this task can be challenging because the balloon is necessarily in the uninflated state when mounted on a catheter thereby making it difficult to distinguish between the various portions of the balloon. The problem is exacerbated when dealing with an uninflated, foldable balloon.
The tolerance errors associated with the production of balloons and the mounting of a balloon on a catheter and in mounting the stent to the balloon can compound leading to a stacking of tolerance errors. The tolerance errors are increased when the balloon is positioned relative to marker bands that have been mounted on the catheter.
To that end, there is a need for improved methods of positioning a balloon on a catheter, for positioning an expandable, implantable medical device on a balloon and for maintaining the positioning of the device once it is on the balloon.
There is also a need for balloons whose various portions may be readily identified even in the uninflated state of the balloon to facilitate mounting of the balloon on a catheter and/or mounting a medical device thereon.
For the purpose of this disclosure, the term expandable, implantable medical device shall refer to stents, grafts, stent-grafts and vena cava filters, whether self-expandable, balloon expandable or otherwise expandable.
All U.S. patents and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
The present invention relates to medical balloons with a textured, partially textured or otherwise marked surface. The texturing or marking facilitates the positioning of an expandable, implantable medical device on the balloon and increases the securement of a stent or other expandable, implantable medical device to the balloon.
In one embodiment, the inventive balloons are marked via a variation in the opacity of the balloon material in the regions to be marked.
In another embodiment, the inventive balloons are marked via one or more protrusions or dimples in the desired region of the balloon.
In yet another embodiment, the inventive balloons are marked by a different texture in the marked region.
The invention contemplates marking the balloons in at least one of several desired regions in particular. These desired regions include the center of the balloon and the proximal and distal cone/body interfaces.
The invention is also directed to methods of positioning a balloon on a catheter and to methods of positioning a stent or other medical device on a balloon using the inventive marked balloons.